amphibious drive

[metinker]

I've been thinking about amphibious vehicle design and it seems the greatest challenge is the land drive wheels.

Prior art seems to mostly consist of truck axles. Rudimentary and lots of places for water to penetrate and damage bearings, brakes and gears.

Later generations apear to be CV type axle shafts outboard of the hull. Better because differentials and brakes can be isolated from water. Still alot of potential for bearings to be contaminated and certainly doesn't lend itself to salt water.

What other ways might there be to support wheels and tires while applying a driving force?

 

[jmw]

Could try asking Tim Dutton...

http://www.amphijeep.biz/

I look across the river at his new works on the Arun and there are usually one or two Amphijeeps outside and occasionally an Amphijeep will go for a cruise in the river.
On the web site you will see a couple of them crossed the English Channel.

On the website he says only:

Early amphibious cars had no problems with low powered, cool lamps but today's modern lamps run hot and it is not possible to drive into water with them switched on without cracking the glass, for this reason every front and rear lamp on the Amphijeep is protected with high impact 5/16" (8mm) clear acrylic plastic so none of the lamps can ever contact the water.

Special attention has been paid to the sealing of the prop shafts (the only components going thru the hull). {/quote]

JMW

http://www.ViscoAnalyser.com

 

[RobWard]

That site also states:

Axle suck

* When a car is driven on the road the brakes and axles always heat up. If the car is then driven into water the temperature of the axles suddenly drops due to the water always being colder than the surrounding air. This causes the air trapped inside the axles to contract very quickly - so quickly that the negative pressure actually sucks water passed the oil seals into the axle with dire results. This phenomenon is called axle suck. On the Amphijeeps both axles are vented to air (well above the water line) so any sudden pressure drop is accommodated with no effect.

"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams

 

[jmw]

Sounds simple when you know how.

JMW

http://www.ViscoAnalyser.com